Fluid selection system



Feb. 25, 19 69 M. R. RUSSINIK 3,429,508

' FLUID SELECTION SYSTEM Filed Aug. 25, 1966 1N VEN TOR. M/d/MELEEUSS'M/l( I BY United States Patent 3,429,508 FLUID SELECTIGN SYSTEMMichael R. Rnssinik, Minneapolis, Minn., assignor to Gray Company, Inc.,Minneapolis, Minn., a corporation of Minnesota Filed Aug. 25, 1966, Ser.No. 575,026

US. Cl. 239-126 Claims Int. Cl. B05b 7/04, 7/26 ABSTRACT OF THEDISCLOSURE A fluid selection system for selectively spraying at leasttwo fluids, such as water and a soap or detergent and water solution.The system includes a constant flow rate fluid pump, and the outlet ofthe pump is connected with a spray gun having two different sized sprayorifices so that the outlet pressure of the pump depends on which of thetwo orifices is being used for spraying. The inlet of the pump isconnected with containers for the fluids to be sprayed, and a valve ispositioned in a conduit interconnecting one of the containers and theinlet of the pump for controlling the flow through the conduit. Thevalve is actuated by a spring biased piston, one face of which isdirectly exposed to the outlet pressure of the pump so that the pistonmoves, and thus the valve is opened or closed, in response to thevariation in the outlet pressure of the pump caused by selectively usingone or the other of the orifices on the spray gun for spraying.

The invention relates to a novel and improved fluid selection system,and more specifically, to a novel and improved fluid selection systemparticularly adapted to be used in industrial spray cleaning equipmentwherein a relatively high pressure spray of water or alternatively,detergent solution, is used for cleaning.

In the past, equipment for a variety of purposes has required fluidsystems wherein a plurality of fluids could be selectively sprayedthrough a common nozzle. To achieve this result, many different types offluid selection systems have been developed.

An example of equipment requiring such a fluid selection system isindustrial spray cleaning equipment which utilizes a high pressure sprayof either water or detergent solution to clean accumulated dirt, grimeand grease from machinery, motor vehicles and the like. Commerciallyavailable cleaning equipment includes a pump, a plurality of fluidreservoirs and a spray gun, which may be connected to the pump outlet bymeans of hose or other flexible conduit. A number of electricallyactuated valves and switches are utilized to control which of aplurality of fluids is to be sprayed from the spray gun. Forconvenience, the switches are mounted on the spray gun so that the userof the gun does not have to stop spraying and return to the pump when itis desired to change the fluid being sprayed. While this fluid selectionsystem performs satisfactorily, the cost of the valves and switches usedin the system significantly increases the over-all cost of theequipment.

It has also been suggested that a satisfactory fluid selection systemfor spray cleaning equipment could be obtained by using a pressurerelief valve, positioned in the conduit interconnecting the pump andspray gun, to actuate an electrical switch that, in turn, controls anelectrically actuated valve in the conduit connecting the inlet of thepump to a source of water. In this system, the relief valve is actuated,and thus the particular fluid being sprayed is changed every time thatthe trigger of the spray gun is released, e.g., every time the manuallyactuated valve in the spray gun is opened and closed by the user of thegun. While this system does require fewer electrically actuated valvesand switches and thereby does somewhat reduce the over-all cost of thecleaning equipment, the system does not permit a real selection of thefluids to be sprayed since every time the gun is used, a different fluidis sprayed. In other words, it is impossible to continuously spray onlyone fluid from the gun if the trigger of the gun is not continuouslydepressed. Thus, this system is obviously inconvenient, and in somecases, impractical to use.

Briefly and in contrast, this invention provides a greatly simplified,highly reliable and relatively inexpensive system for selectivelyspraying a plurality of fluids. As noted above, this novel and improvedfluid selection system has particular utility in industrial spraycleaning equipment. In this system, selection of the fluid to be sprayedis achieved by controlling the pump outlet pressure or in other words,the pressure of fluid in the conduit connecting the pump to the spraygun. Valve means, positioned in the conduit connecting one of the fluidreservoirs to the pump and directly responsive to the pump outletpressure, permits the flow of fluid through the conduit when the pumpoutlet pressure exceeds a predetermined value and prevents flow of fluidthrough the conduit when the pump outlet is less than the predeterminedvalue. In the preferred embodiment of this invention, the pump outletpressure is controlled by selectively using different sized sprayorifices in the gun for spraying. In other words, a certain size sprayorifice is used when one fluid is to be sprayed, while a different sizeorifice is used when another fluid is to be sprayed.

A primary object of this invention is to provide a novel and improvedfluid selection system for selectively spraying a plurality of fluidsfrom a nozzle or spray gun, which system has particular utility inindustrial spray cleaning equipment.

Another object of the present invention is to provide a novel andimproved fluid system for spraying a plurality of fluids in which thepump outlet pressure is utilized to control the selection of the fluidto be sprayed.

Another object of the present invention is to provide a novel andimproved fluid selection system in which valve means is positionedwithin a conduit connecting one of the fluid reservoirs with the inletof the pump and is responsive to the pump outlet pressure whereby flowthrough the valve means is permitted when the pump outlet pressureexceeds a predetermined value and flow is prevented through the valvemeans whenever the pump outlet pressure is less than the predeterminedvalue.

Still another object of the present invention is to provide a novel andimproved fluid selection system wherein the pump outlet pressure iscontrolled by using ditferent sized spray orifices, i.e., the sprayorifices having different effective diameters. A related object of thepresent invention is to provide a spray tip assembly mounted on thespray gun, the assembly having two different sized spray orifices andpermitting the user of the system to change quickly and easily from oneorifice to the other and thereby control which of two fluids is to besprayed from the spray gun.

Another object of the present invention is to provide a novel andimproved fluid selection system particularly useful in industrial spraycleaning equipment, which system primarily utilizes standard,commercially available components and does not require the use ofrelatively expensive electrically actuated valves and switches.

These and other objects and advantages of the invention will becomeapparent from the following description of the preferred embodiment ofthe invention described in conjunction with the following drawing inwhich:

FIGURE 1 is a schematic view of the novel and improved fluid selectionsystem of this invention as used for industrial spray cleaning, andincluding an enlarged vertical cross-sectional view of the pressureresponsive valve means;

FIGURE 2 is a partial vertical cross-sectional view of the spray tipassembly; and

FIGURE 3 is a perspective view of the spray tip member showing the twodifferent size spray orifices formed therein.

Referring now to FIGURE 1, the improved fluid selection system .11 ofthis invention includes a tank or reservoir 12 which provides a sourceof the base or the principal fluid to be sprayed. A second tank orreservoir 13 provides a source of the additive or the secondary fluidwhich may be mixed with the base fluid, in desired proportions, andsprayed as more fully explained hereinbelow. When this improved systemis used for industrial cleaning equipment, it will be understood thatthe base fluid is water and the additive fluid is a soap or detergentsolution.

This tank 12 communicates with the inlet 14 of a pump 15 through conduit16. Note that the end of the conduit 16 which extends within the tank 12has a conventional strainer 17 connected thereto whereby any solidparticles in the base fluid are prevented from entering the fluidsystem. The additive fluid in the tank 13 communicates with the inlet 14of the pump 15 through a conduit 18, 'valve means 19, conduit 21,adjustable restrictor 22 and the conduit 16. Of course, if desired, theconduit 21 may be connected directly to pump inlet 14.

The pump 15 may be either a conventional rotary or reciprocating pumpwhich is continuously driven by a motor means, not shown, and whichcreates a suction at its inlet 14 during operation. The flow rate of thepump must remain constant regardless of the outlet pressure of the pump.

The outlet 23 of the pump is in fluid communication with a conventionalspray gun 24 through a conduit 25. The spray gun 24 has a manuallyoperated trigger 26 which permits the user of the spray gun to controlthe flow of fluid through the gun. A spray gun which may be used is theModel 205-939 spray :gun manufactured and sold by the Gray Company, Inc.of Minneapolis, Minn. Conduit 27 permits recirculation of the fluid fromthe gun back to the inlet 14 of the pump 15 when the spray gun is notbeing used.

The valve means 19 comprises a generally cylindrical body 28 which hasan internal chamber 29 formed therein. The chamber 29 is divided intofirst and second portions 31 and 32, respectively, by an annular,radially inwardly projecting flange 33. A centrally disposed aperture 34is formed in the flange 33 and permits fluid communication between theportions 31 and 32 of the chamber 29. The first portion 31 alsocommunicates with the terminal end 35 of the conduit .18 wherebyadditive fluid from the tank 13 may flow unrestrictively into the firstportion 31 of the chamber 29. A conventional fastening and sealing means36 connects the end 35 of the tubing 18 in an aperture 37 formed in theend 38 of the body 28-.

A conventional fastening and sealing means 3-9 connects the tubing 21 inan aperture 40 formed in the side 41 of the body 28 so that the secondportion of the chamber 29 is always in fluid communication with theconduit 21. A branch conduit 42 interconnects portion 32 of the chamber29 with the conduit which, as noted above, connects the pump outlet 23to the spray gun 24. A conventional fastening and sealing means 43connects the end of the conduit 42 to an aperture 43 formed in the end44 of the body 28.

A piston 45 is positioned within the second portion 32 of the chamber29. The outer periphery of the piston is congruent to the interior ofthe portion 32 and the piston is of such a size that it freely slideswithin the portion 32 of the chamber. However, to insure that no fluidleakage occurs across the piston, a sealing ring 46 is positioned in agroove 47 formed about the periphery of the piston.

As shown in FIGURE 1, one face 48 of the piston 45 is exposed to thefluid in branch conduit 42 a d the Pressure exerted by this fluid, ofcourse, urges the piston 45 to move to the left from the position shownin FIGURE 1. The other face 49 of the piston has a centrally disposedshaft 50 projecting therefrom which extends through the aperture 34 inthe flange 33 The shaft 50 carries a valve assembly 51 at the end 52,remote from the piston 45. This valve assembly is secured to the end ofthe shaft by a retaining screw and washer 53, and consists of atruncated conically shaped, annular valve member 54 which may be formedof resilient, wear-resistant material. The length of the shaft isselected so that when the piston is in the position shown in FIGURE 1,the valve member 54 contacts the edge 55 of the flange 33 which servesas a valve seat. Thus, when the valve member 54 is in this position,fluid communication between the portion 31 and the portion 32 of thechamber 29 is prevented whereby the flow of additive fluid from the tank13 to the pump inlet 14 is interrupted.

A coil compression spring 56 is positioned between the flange 33 and theface 49 of the piston 45. This spring 56 biases the piston toward theposition shown in FIG- URE 1. As noted above, the face 48 of the pistonis exposed to the fluid in the branch conduit 42. However, the forceexerted by the coil spring 56 on piston 45 is such that until thepressure of a fluid in the conduit 42 exceeds a certain predeterminedvalue, the piston remains in the position shown in FIGURE 1. Moreover,as explained above, when the piston 45 is in that position, the valvemember 54 contacts the valve seat 55 thereby preventing fluidcommunication between the portions 31 and 32 of the chamber 29. However,when the fluid pressure in the conduit 42 exceeds the predeterminedvalue, the fluid force acting on the face 48 of the piston 45 overcomesthe bias of the spring 56 and the piston moves to a second position, tothe right of that shown in FIGURE 1. This movement of the piston causesa concomitant movement of the valve 54 away from seat 55 therebypermitting fluid communication between the tank 13 and the inlet 14 ofthe pump 15. In this second position, the face 49 of the piston 45 isadjacent the edge of the aperture 40 but never blocks flow through theaperture 40.

The adjustable restrictor 22 positioned in conduit 21 between valvemeans 19 and conduit 16 may be a conventional adjustable needle valve,As mentioned above, the function of this restrictor is to control thevolume or proportion of additive fluid flowing to the pump inlet 14,relative to the volume of base fluid.

The pressure of the fluid flowing in conduit 25 and thus in conduit 42is controlled by varying the size or the effective diameter of the sprayorifice of the spray gun 24. By decreasing the size or the effectivediameter of the spray orifice of the gun 24, the pressure in conduits 25and 42 is increased and conversely, when the eflective size or diameterof the spray orifice of the gun 24 is increased, the pressure inconduits 25 and 42 is decreased.

This change in the diameter of the spray orifice is accomplished by theutilization of a dual spray tip assembly 57 as shown in FIGURES 2 and 3.The spray tip assembly 57 is described in detail in United StatesLetters Patent No. 3,116,882 and is sold by the Gray Company, Inc. ofMinneapolis, Minn. Briefly, this assembly comprises a generallyball-shaped member 58 which is positioned within the fitting 59 so as topermit relative rotation between the ball member 58 and the fitting, butprevents leakage of fluid therebetween. The fitting 59, which isattached to the end of the barrel 60 of the spray gun by a threaded nut61, is generally cylindrical in shape and has an axial passageway 62formed therethrough which, at one end, permits fluid communicationbetween the ball member 58 and the fluid passage (not shown) formed ingun 24 and which, at the other end, provides an opening through whichfluid may be sprayed from the gun. The ball member has two intersectingpassages 63 and 64 drilled therein with longitudinal axes of thepassages being spaced from each other. Thus, when one of the passages 63and 64 is aligned with the passageway 62, the other passage isperpendicular to the passageway. Moreover, because of the close fitbetween the ball member 58 and the fitting 59, fluid only flows throughthe passage aligned with the passageway 62. The passages 63 and 64 haveconventional spray orifices 65 and 66, respectively, positioned at oneend thereof with the orifice 66 having a larger effective diameter thanthe orifice 65.

The ball member 58 includes a shaft 67 which projects up through asleeve 68 formed on the fitting 59. The upper end of the shaft 67 has ahandle 69 attached thereto by the lock nut 70. By rotating this handlethrough a 90 are, the user of the gun may select which of the two sprayorifices 65 and 66 will be used for spraying. Of course, since thesespray orifices have different effective diameters, and since thecapacity or flow rate of the pump remains constant, the fluid pressurein the conduit 25 will depend on which of the orifices is being used tospray fluid.

As shown in FIGURE 1, conventional check valves 71 and 72 are positionedin conduits 16 and 18, respectively, so as to prevent back flow of fluidin those lines.

In a specific example of the improved fluid selection system of thisinvention, the pump 15 is a 550 p.s.i. pump having a two gallon perminute capacity at a maximum of 550 p.s.i. The spray orifice 65 has aneffective diameter of 0.062 inch and at the flow rate of two gallons perminute, the pressure of the fluid in conduits 25 and 42 is maintained at450 p.s.i. The other spray orifice '66 has an effective diameter of0.078 inch and at the flow rate of two gallons per minute, the pressureof the fluid in conduits 25 and 42 is maintained at 160 p.s.i. The forceof the spring 56 is selected so that when fluid is sprayed throughorifice 65, and thus a pressure of 450 p.s.i. exists in conduits 25 and42, the force of the fluid acting on face 48 of the piston 45 overcomesthe force of spring 56, and the piston 45 and thus valve assembly 51 aremoved to the left from the position shown in FIGURE 1, therebypermitting additive fluid to flow from the tank 13 to conduit 16. Ofcourse, the specific proportion of additive fluid in the mixture ofadditive and base fluid sucked into the pump inlet 14 depends on thesetting of the adjustable restrictor 22.

When the user of the spray gun rotates the handle 69 so that the sprayorifice 66 is used for spraying, the resultant fluid pressure inconduits 25 and 42 is insufficient to overcome the force of the spring56. Thus, the spring returns and retains the piston 45 and valve 52 tothe position shown in FIGURE 1 and flow of additive fluid from the tank13 to the pump inlet is stopped. At this time, only base fluid issprayed from the gun.

Of course, rather than using the nozzle assembly 57 described above, thesame functional results may be achieved by using separate spray tipassemblies having different effective diameter spray orifices. Oneassembly could be threaded onto the end of the barrel 60 of the spraygun 24 when the operator desires to spray base fluid alone and thatassembly could be removed and another assembly threaded onto the end ofthe barrel when a mixture of additive and base fluid was to be sprayed.Of course, using separate spray tip assemblies would be more timeconsuming and cumbersome than using the assembly 57.

Therefore, in view of the above, it is apparent that the novel andimproved fluid selection system of this invention provides an improved,simplified and trouble-free system for selecting whether the base fluidalone or a mixture of an additive and a base fluid will be sprayed froma spray gun. This system utilizes inexpensive, commercially availablecomponents and provides a reliable and relatively inexpensive system.

Moreover, it should be noted that while the improved fluid selectionsystem of this invention has been described herein with reference toindustrial spray cleaning equipment, the system may be used with otherequipment. Furthermore, while in the preferred embodiment only twodifferent fluids are shown, additional fluids may be used byincorporating additional valve means, similar to valve means 19, intothe system which valve means operate in response to higher pump outletpressures. Of course, additional spray orifices would have to be used soas to achieve the higher pump outlet pressure.

This invention may be embodied in other specific forms which do notdepart from the spirit or essential characteristics thereof. Thepreferred embodiment is therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescriptions and all changes which come Within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

I claim as my invention:

1. An improved fluid selection system particularly adapted for use inindustrial spray cleaning equipment comprising: a constant flow ratefluid pump having an inlet and outlet; nozzle means having a sprayorifice for spraying fluid under pressure therefrom; first conduit meansfor connecting the pump outlet with the nozzle means; means forselectively maintaining the pressure of the fluid in the first conduitmeans at either a first pressure or a second pressure; a first source offluid; a second source of fluid; second conduit means for connecting thefirst source of fluid with the pump inlet; third conduit means forconnecting the second source of fluid with the pump inlet; and valvemeans, including fluid pressure responsive valve actuating means, forcontrolling the flow of fluid through the third conduit means; fourthconduit means for connecting the fluid responsive means of the valvemeans with the pump outlet whereby when the fluid in the first conduitmeans is maintained at said first pressure, a valve means permits flowof fluid through the third conduit means and when the fluid in the firstconduit means is maintained at said second pressure, the valve meansprevents the flow of fluid through the third conduit means.

2. The system described in claim 1 in which said first pressure isgreater than said second pressure.

3. The system described in claim 1 including means positioned in thethird conduit means for adjustably controlling the volume of fluid flowthrough the third conduit means, relative to the volume of fluid flowthrough the second conduit means.

4. The system described in claim 1 in which the valve means comprises abody in fluid communication with the third conduit means; a pistonslidable in the body and having one face thereof in communication withthe fluid in the first conduit means whereby the pressure of the fluidin the first conduit means biases the piston to a first position; springmeans biasing the piston to a second position spaced from the firstposition; a valve element carried by the piston and a valve seat formedin the body and spaced from the piston whereby when the fluid in thefirst conduit means is at said second pressure, the piston is moved tothe second position so that the valve element engages the valve seat andwhen the fluid in the first conduit means is at said first pressure, thepiston is moved to the first position so that the valve element isspaced from the valve seat.

5. The system described in claim 1 in which the pressure maintainingmeans is carried by the nozzle means.

6. The system described in claim 1 in which the pressure maintainingmeans includes a member carried by the nozzle means and having first andsecond passages formed therein for fluid communication with the firstconduit means; the passages being of different diameters; means forselectively placing either the first or second passage in fluidcommunication with the first conduit means whereby when the firstpassage is placed in communication with the first conduit means, thepressure of the fluid in the first conduit means is maintained at saidfirst pressure and when the second passage is placed in communicationwith the first conduit means, the pressure of the fluid in the firstconduit means is maintained at said second pressure.

7. The system described in claim 4 in which the central longitudinalaxis of the valve element, the valve seat and the piston are coaxial.

8. The system described in claim 5 in which the pressure maintainingmeans includes means for changing the effective diameter of the sprayorifice of the nozzle means.

9. The system described in claim 6 in which the member is ball-shapedand the terminal ends of the first and second passages form sprayorifices for the nozzle means, and in which the eifective diameter ofthe spray orifice in the first passage is less than the effectivediameter of the spray orifice in the second passage.

10. The system described in claim 9 in which the valve means comprises abody in fluid communication with the third conduit means; a pistonslidable in the body and having one face thereof in communication withthe fluid in the first conduit means whereby the pressure of the fluidin the first conduit means biases the piston to a first position; springmeans biasing the piston to a second position spaced from the firstposition; a valve element carried by the piston and a valve seat formedin the body and spaced from the piston whereby when the fluid in thefirst conduit means is at said second pressure, the piston is moved tothe second position so that the valve element engages the valve seat andwhen the fluid in the first conduit means is at said first pressure, thepiston is moved to the first position so that the valve element isspaced from the valve seat.

References Cited UNITED STATES PATENTS 3,049,302 8/1962 Simmons 239-1263,116,882 1/1964 Vork 239391 X 3,140,049 7/1964 Norstrud et a1. 239-126STANLEY H. TOLLBERG, Primary Examiner.

US. Cl. X.R.

